RE: Where to Buy Mahle Piston Cylinder Assembly for 4.2
If its really a 4.2 then it is probably part of a Sachs Dolmar saw or concrete cutter. Sachs Dolmar is now Sachs Makita and you should be able to get parts for it from a good saw shop.
If its really a Mahle cylinder but is not a 4.2 it could be a Partner, Husqvarna or ??? Mahle makes cylinders and pistons for about half the free world 2c engines.